System and method for selective trimerization

Abstract

Disclosed herein is a method for separating from the reactor effluent of an olefin oligomerization procedure those catalyst materials and polymeric by-products which can cause difficulties in the downstream processing of such effluent. Polymer by-products and catalyst in the effluent are separated from reaction products by flash vaporization utilizing an in-situ hot solvent which is contacted with the effluent and serves as the heating medium to promote this flash vaporization step. Subsequent processing of a liquid portion of the effluent which is left after flash vaporization involves recovery of catalyst and polymeric by-products therefrom in a steam stripping vessel. Also disclosed is a multiple reactor system which can be used for continuous trimerization of ethylene to 1-hexene while at the same time washing polymeric by-products from one of the reactors in the series using a wash oil solvent.

Description

PRIORITY CLAIM[0001]This application is a National Stage Application of International Application No. PCT / US2010 / 026661 filed Mar. 9, 2010, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION[0002]The invention described herein relates to especially effective means and procedures for separating olefin products like 1-hexene, unreacted reactants such as ethylene and diluents from catalyst material and polymeric by-products found in a reactor effluent from an olefin oligomerization, e.g., trimerization, process. The invention described herein also relates to apparatus and processes for continuously oligomerizing, e.g., trimerizing, olefins such as ethylene to provide such oligomer-containing, e.g., 1-hexene-containing, reactor effluent without necessarily having to interrupt reactor effluent flow during reactor maintenance and cleaning to remove polymeric foulants.BACKGROUND OF THE INVENTION[0003]1-Hexene can be produced in high selectivity via ethylene tr...

AI Technical Summary

Problems solved by technology

Prior art methods for dealing with the presence of active catalyst and polymer by-products in the trimerization reactor effluent have encountered some problems.

This exceedingly high excess requirement for alcohol is costly, and also requires the addition of a distillation column for recovery of the unreacted alcohol for efficient utilization of the alcohol.

Prior art methods for separating polymer by-product from the reactor effluent can also be cumbersome.

As the polymer is concentrated through successive distillation steps to recover reactants, products, and diluents, the polymer can precipitate and foul the column internals and reboilers.

Finally, build-up of polymeric by-product which remains within the oligomerization reactor itself and in associated reactor piping can be troublesome.

Shutting down of the reactor(s) for cleaning and maintenance is, of course, economically disadvantageous because production of the desired oligomerization product is interrupted.

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